The Polish workers' successful bid to establish free trade unions offers a direct challenge to the orthodox Soviet-style communist government. Apart from Czechoslovakia's short-lived freedom in 1968, only Hungary has managed to put some distance between itself and orthodox Soviet policies, giving it the most liberal economy in the East bloc.

The challenge to the Soviet empire is evident in the mistrust voiced from the start of the Baltic strikes by the Soviets and vitually all the East European leaders over the radical new course Poland was taking.

Hard-line regimes in East Germany and Czechoslovakia were soon calling them Western-backed "counterrevolution" that would "damage socialism on Polish soil."

Romania's President Ceausescu adopted a similar hard-line view and criticized the Polish leadership under the since-deposed Edward Gierek. It was a significant contrast from his oft-insisted theme of noninterference in the affairs of other communist parties or countries. But his hard-line comments were in line with his policies at home.

East Germany, Czechoslovakia, and Romania have these reasons to be concerned about how the example of the Polish workers might affect their own working populations:

* East Germany has the most to fear. It is constantly exposed to West German media coverage of the strike depicting the tremendous show of unity and solidarity among the Polish workers. What gives the East German leadership sleepless nights is the threat that East German workers will be influenced by events next-door and stage similar protests.

* Czechoslovakia, despite its hard-line government, has a strong labor union tradition. Even if the workers are momentarily subdued, they have not completely forgotten 1968, when liberal forces under Alexander Dubcek enjoyed a brief term in office before Soviet tanks rolled in Prague.

* Romania has had its own worker-government confrontation. Three years ago miners went on strike in the Jiu coal valley. It took a carrot-and-stick approach by the government to bring unrest under control. While the government applied rigorous police action, it pledged consumer gains.

The Polish events prompted the Romanian leader to visit the area again and to inspect no fewer than 12 of Bucharest's food markets in a new show of concern for the consumer.

By East-bloc standards, workers in East Germany and Czechoslovakia are not badly off. But they cannot be regarded as immune to recent events in neighboring Poland.

Domestic frustratioins weigh even more heavily in Romania. Its living standrds lags behind all others in the bloc, and Mr. Ceausescu is as concerned as anyone else at the appearance of Poland's new, independent unions and their successful stand against efforts to tie them to the Communist Party.

Whatever its frequent differences with the Soviet Union on foreign policy, the Romanian Communist Party maintains as firm a domestic grip as any other East-bloc party.

Only Hungary (which is likely to be the primary model for economic reform in Poland) remained calm about the strikes. Its news media reported their progress from the start. Nor did they balk at a full and fair account of the Aug. 31 strike settlement accords, including the right to strike.

Hundary's partially market-oriented reform was launched 12 years ago. At that time it also accepted a logical outcome -- greater latitude for trade unions, which gained a right of veto in many enterprise decisions.